Mission-Oriented Autonomy for Intelligent, Adaptive, and Multi-Agent Remote Sensing of Ice Sheets using Unmanned Aerial Systems

Throughout our history, humanity has been developing and progressing technology in order to help us better understand the world in which we live. As climate change becomes an increasingly urgent global crisis, scientists have been tasked with developing models for better understanding the complex dynamics involved, as well as to more accurately forecast the long term effects on our environment. With respect to sea level rise, both our knowledge of these dynamics and the accuracy of these models can be improved through the routine collection of crucial data concerning glacier ice thickness and bedrock topology. To accomplish this, innovative solutions are being developed by groups of inter-disciplinary research teams, combining fields such as earth-science, radar systems, data science, and aerospace engineering. Through this collaboration, we have the potential to leverage breakthroughs in unmanned systems technology and miniaturized, specialized sensors for comprehensive, precise, and routine data collection of key polar research objectives. As Unmanned Aerial Systems (UASs) have become more reliable research platforms in recent years, they now have the capability to perform these remote sensing operations at a reduced cost compared to manned operations, while also providing repeatable, precision tracking capabilities along flight lines, enabling the surveying of tightly-spaced grids, and removing human flight crews from hazardous polar environments. However, the payload, range, and wind constraints for these platforms severely restrict their operational sensing footprint. Additionally, UASs generally have a much smaller wingspan compared to manned aircraft typically used in Earth Science missions, which becomes a challenging factor for incorporating efficient directive antennas at the low operating frequencies required for glacial sounding. The aim of this work is to address these issues and to enhance mission efficiency and the overall quality of data collection for these operations through the implementation of onboard mission-oriented autonomy that includes cognitive decision-making for intelligent survey operations, adaptive functionalities, and a scalable, robust framework for multi-agent operations. As opposed to conventional methods for polar research operations which generally involve single-agent missions, using standard waypoint guidance and fixed-routes planned by human operators, the unique contributions of the developed mission-oriented autonomy in this work include: 1) Automated flight line generation for rapid and reliable mission planning of tightly-spaced flight lines required for cross-track synthetic aperture radar processes and surface clutter suppression, with required spacing based on the operating frequency of the onboard radar system. 2) Implementation of Dubins Path guidance methods into polar research operations for precision end-to-end survey of mission flight lines while taking into account the kinematic constraints of the fixed wing aircraft, as well as for efficiently traversing to and from a home loiter location during mission operations. 3) Cognitive, real-time optimal path planning through mission flight lines utilizing both deterministic and stochastic Traveling Salesman Problem heuristics. 4) Modifications to these Traveling Salesman Problem heuristics for ensuring safe, feasible, and reliable operations in real-time by taking into account aircraft range constraints. 5) Collaborative Multi-Agent survey operations utilizing space partitioning and Hungarian Assignment for distributed task allocation, as well as morphing potential fields for collision avoidance. 6) Modifications for Multi-Agent deployment scheduling to reduce inter-agent interference for sensitive radar systems to improve coherency of the collected data, and to rapidly and efficiently deploy agents into and out of survey areas. 7) Modifications for Heterogeneous flight operations for increasing operational capabilities through cross-platform collaboration. 8) Failsafe features to instill robustness in Multi-Agent operations with respect towards accommodating and adapting to single-agent system failures, by automatically re-planning collaborative survey operations. In this work, the motivation for the creation of this mission-oriented autonomy is discussed, along with the methodology of each of the autonomy features, and the framework for implementation onto UAS platforms. Case studies are conducted for past and future polar research deployments using unmanned systems to assess the potential improvements in operational capabilities and data collection for the developed autonomy compared to conventional methods. Finally, the developed autonomy is implemented onto an embedded system for preliminary flight testing and validation, as well as used for intelligent mission planning for a manned operation

The Effect of Organic Matter on Maximum Compactability of Soil

Bulk density is the weight of a given volume of soil expressed by soil scientists as grams per cubic centimeter (g/cm3). The higher the bulk density, the lower the volume of soil occupied by pore space, that volume of soil in which air and water reside. Because of this, there is much interest on the degree to which soil can be compacted. The Proctor test is a means of determining the maximum bulk density that can be attained in a soil sample. This maximum compactibility is widely used on highways and building foundations but has had little use in agricultural soils. In the fall of 1994 we began to determine maximum compactability on samples from plots and fields with variable land use history in Kentucky. This is a report of the preliminary results

Functional consequences of subunit diversity in RNA polymerases II and V

SummaryMultisubunit RNA polymerases IV and V (Pol IV and Pol V) evolved as specialized forms of Pol II that mediate RNA-directed DNA methylation (RdDM) and transcriptional silencing of transposons, viruses, and endogenous repeats in plants. Among the subunits common to Arabidopsis thaliana Pols II, IV, and V are 93% identical alternative ninth subunits, NRP(B/D/E)9a and NRP(B/D/E)9b. The 9a and 9b subunit variants are incompletely redundant with respect to Pol II; whereas double mutants are embryo lethal, single mutants are viable, yet phenotypically distinct. Likewise, 9a or 9b can associate with Pols IV or V but RNA-directed DNA methylation is impaired only in 9b mutants. Based on genetic and molecular tests, we attribute the defect in RdDM to impaired Pol V function. Collectively, our results reveal a role for the ninth subunit in RNA silencing and demonstrate that subunit diversity generates functionally distinct subtypes of RNA polymerases II and V

Mannose binding lectin is required for alphavirus-induced arthritis/myositis

Mosquito-borne alphaviruses such as chikungunya virus and Ross River virus (RRV) are emerging pathogens capable of causing large-scale epidemics of virus-induced arthritis and myositis. The pathology of RRV-induced disease in both humans and mice is associated with induction of the host inflammatory response within the muscle and joints, and prior studies have demonstrated that the host complement system contributes to development of disease. In this study, we have used a mouse model of RRV-induced disease to identify and characterize which complement activation pathways mediate disease progression after infection, and we have identified the mannose binding lectin (MBL) pathway, but not the classical or alternative complement activation pathways, as essential for development of RRV-induced disease. MBL deposition was enhanced in RRV infected muscle tissue from wild type mice and RRV infected MBL deficient mice exhibited reduced disease, tissue damage, and complement deposition compared to wild-type mice. In contrast, mice deficient for key components of the classical or alternative complement activation pathways still developed severe RRV-induced disease. Further characterization of MBL deficient mice demonstrated that similar to C3(-/-) mice, viral replication and inflammatory cell recruitment were equivalent to wild type animals, suggesting that RRV-mediated induction of complement dependent immune pathology is largely MBL dependent. Consistent with these findings, human patients diagnosed with RRV disease had elevated serum MBL levels compared to healthy controls, and MBL levels in the serum and synovial fluid correlated with severity of disease. These findings demonstrate a role for MBL in promoting RRV-induced disease in both mice and humans and suggest that the MBL pathway of complement activation may be an effective target for therapeutic intervention for humans suffering from RRV-induced arthritis and myositis.This work was supported by NIH/NIAMS R01 AR 047190 awarded to MTH

Susceptibility Provision Enhances Effective De-escalation (SPEED): utilizing rapid phenotypic susceptibility testing in Gram-negative bloodstream infections and its potential clinical impact

Abstract Objectives We evaluated the performance and time to result for pathogen identification (ID) and antimicrobial susceptibility testing (AST) of the Accelerate Pheno™ system (AXDX) compared with standard of care (SOC) methods. We also assessed the hypothetical improvement in antibiotic utilization if AXDX had been implemented. Methods Clinical samples from patients with monomicrobial Gram-negative bacteraemia were tested and compared between AXDX and the SOC methods of the VERIGENE® and Bruker MALDI Biotyper® systems for ID and the VITEK® 2 system for AST. Additionally, charts were reviewed to calculate theoretical times to antibiotic de-escalation, escalation and active and optimal therapy Results ID mean time was 21 h for MALDI-TOF MS, 4.4 h for VERIGENE® and 3.7 h for AXDX. AST mean time was 35 h for VITEK® 2 and 9.0 h for AXDX. For ID, positive percentage agreement was 95.9% and negative percentage agreement was 99.9%. For AST, essential agreement was 94.5% and categorical agreement was 93.5%. If AXDX results had been available to inform patient care, 25% of patients could have been put on active therapy sooner, while 78% of patients who had therapy optimized during hospitalization could have had therapy optimized sooner. Additionally, AXDX could have reduced time to de-escalation (16 versus 31 h) and escalation (19 versus 31 h) compared with SOC. Conclusions By providing fast and reliable ID and AST results, AXDX has the potential to improve antimicrobial utilization and enhance antimicrobial stewardship

An Assessment of Water Sources Related to Major Systems of Agricultural Land Use in Kentucky

Recent years have seen a greater public concern about the quality of the nation\u27s water resources. While initial concerns targeted point source pollution, the emphasis in recent years has shifted to non-point source pollution, including the effect of general practices used by fanners in agricultural production systems. Since there was no reliable data base on such effects for Kentucky, the state\u27s General Assembly passed legislation during its 1990 session directing the University ofKentucky\u27s College of Agriculture (UK.CA) to assess the effect of agricultural practices on quality of the state\u27s waters. As part of the efforts undertaken by the UKCA in this regard, an assessment was made of water sources in major agricultural areas to determine the current level of water quality associated with agricultural practices in those areas. This information was needed to evaluate the question of concern: Do nonpoint agricultural practices such as fertilizer and herbicide use and grazing of pastures by livestock pose a threat to the quality of water potentially serving as human drinking water sources

Analysis of an Evidence-based Pediatric Asthma Management Tool for Providers Confirms Linkages between Asthma and Known Risk Factors in a Vermont Practice

Introduction: Pediatric asthma is one of the largest targets for innovative programs in chronic care management due to its extensive and expanding health burden. A physician-directed asthma management, diagnostic and data tracking tool was implemented in a Vermont pediatric practice. Data were analyzed after one year to enable the Vermont Department of Health (VDH) and practice to describe program participants. Methods: A modified version of a validated pediatric asthma survey, Easy Breathing, was administered during office visits at a pediatric practice located in Burlington, VT. Fisher’s exact test was used to assess relationships between those with and without current asthma, and between those with intermittent versus persistent levels of asthma. Results: Of 206 patients, 150 had no asthma, 55 had a current asthma diagnosis and one (1) was listed as ‘unable to determine.’ Patients with current asthma were significantly more likely to be insured with Medicaid (p=.048), have a family history of asthma (p=.019) and be exposed to environmental tobacco smoke (p=.028). Within the asthma group, persistent asthma was associated with exposure to cat (p=.043). Conclusion: Participants in the Easy Breathing Program at this practice with and without current asthma diagnosis showed differences that reflect established asthma risk factors and related asthma triggers. Further efforts are needed to increase the reliability of the data

Massive production of small RNAs from a non-coding region of Cauliflower mosaic virus in plant defense and viral counter-defense

To successfully infect plants, viruses must counteract small RNA-based host defense responses. During infection of Arabidopsis, Cauliflower mosaic pararetrovirus (CaMV) is transcribed into pregenomic 35S and subgenomic 19S RNAs. The 35S RNA is both reverse transcribed and also used as an mRNA with highly structured 600 nt leader. We found that this leader region is transcribed into long sense- and antisense-RNAs and spawns a massive quantity of 21, 22 and 24 nt viral small RNAs (vsRNAs), comparable to the entire complement of host-encoded small-interfering RNAs and microRNAs. Leader-derived vsRNAs were detected bound to the Argonaute 1 (AGO1) effector protein, unlike vsRNAs from other viral regions. Only negligible amounts of leader-derived vsRNAs were bound to AGO4. Genetic evidence showed that all four Dicer-like (DCL) proteins mediate vsRNA biogenesis, whereas the RNA polymerases Pol IV, Pol V, RDR1, RDR2 and RDR6 are not required for this process. Surprisingly, CaMV titers were not increased in dcl1/2/3/4 quadruple mutants that accumulate only residual amounts of vsRNAs. Ectopic expression of CaMV leader vsRNAs from an attenuated geminivirus led to increased accumulation of this chimeric virus. Thus, massive production of leader-derived vsRNAs does not restrict viral replication but may serve as a decoy diverting the silencing machinery from viral promoter and coding region

Massive production of small RNAs from a non-coding region of Cauliflower mosaic virus in plant defense and viral counter-defense

To successfully infect plants, viruses must counteract small RNA-based host defense responses. During infection of Arabidopsis, Cauliflower mosaic pararetrovirus (CaMV) is transcribed into pregenomic 35S and subgenomic 19S RNAs. The 35S RNA is both reverse transcribed and also used as an mRNA with highly structured 600 nt leader. We found that this leader region is transcribed into long sense- and antisense-RNAs and spawns a massive quantity of 21, 22 and 24 nt viral small RNAs (vsRNAs), comparable to the entire complement of host-encoded small-interfering RNAs and microRNAs. Leader-derived vsRNAs were detected bound to the Argonaute 1 (AGO1) effector protein, unlike vsRNAs from other viral regions. Only negligible amounts of leader-derived vsRNAs were bound to AGO4. Genetic evidence showed that all four Dicer-like (DCL) proteins mediate vsRNA biogenesis, whereas the RNA polymerases Pol IV, Pol V, RDR1, RDR2 and RDR6 are not required for this process. Surprisingly, CaMV titers were not increased in dcl1/2/3/4 quadruple mutants that accumulate only residual amounts of vsRNAs. Ectopic expression of CaMV leader vsRNAs from an attenuated geminivirus led to increased accumulation of this chimeric virus. Thus, massive production of leader-derived vsRNAs does not restrict viral replication but may serve as a decoy diverting the silencing machinery from viral promoter and coding regions

Ross River virus envelope glycans contribute to disease through activation of the host complement system

Mannose binding lectin (MBL) generally plays a protective role during viral infection, yet MBL-mediated complement activation promotes Ross River virus (RRV)-induced inflammatory tissue destruction, contributing to arthritis and myositis. As MBL binds to carbohydrates, we hypothesized that N-linked glycans on the RRV envelope glycoproteins act as ligands for MBL. Using a panel of RRV mutants lacking the envelope N-linked glycans, we found that MBL deposition onto infected cells was dependent on the E2 glycans. Moreover, the glycan-deficient viruses exhibited reduced disease and tissue damage in a mouse model of RRV-induced myositis compared to wild-type RRV, despite similar viral load and inflammatory infiltrates within the skeletal muscle. Instead, the reduced disease induced by glycan-deficient viruses was linked to decreased MBL deposition and complement activation within inflamed tissues. These results demonstrate that the viral N-linked glycans promote MBL deposition and complement activation onto RRV-infected cells, contributing to the development of RRV-induced myositis